I have a whole bunch of RF gear at home that I was planning on using for my robot build but I'm having second thoughts as replacement / repair down the track could be problematic.
Initially I was looking at industrial grade transceivers. I was going to connect a PS2 controller to one of these transceivers.

Sorry if this has already been discussed. I'm not familiar with the terminology...
What controller do you use for your robot(s)? Have you switched over from something that didn't work?
Who has rolled their own? What makes your remote 'tick'?
Are there any recommendations for new-comers?

but newer ones seem to be prone to having issues binding when you turn the RX on.

so spektrum radios are probably the gold standard at the moment, others will have better info.

marto has been doing some exciting things with those $5 wifi modules but not live in combat just yet.
A rather long time ago I replaced the brain of an IBC with a "rolled my own" PIC micro controller using a pair of maxtream transcievers, a laptop, visual basic and an X-Box controller. I use the orange-RX stuff now ;->_________________Mechanical engineers build weapons, civil engineers build targets

I mentioned this at the just happened meeting.. But I'll put it in writing here as well for the benefit of all

Most of the newcomers being Engineer/Hackerspace type guys, I recognise and appreicate your interest in developing a prototype for a future "Holographic Control System", and the desire to use an Arduino or other Microcontroller wherever possible..

Quite simply. *Don't.
As Jake said, Invent as few wheels as possible.

It might seem technically boring to use off-the-shelf standard RC gear, but, the fact is, its (relatively) standardised, its reliable, its simple, its proven, and these days, its even cheap ! (It didnt used to be B.H. (Before HobbyKing) ).

For the first few events, you will be dealing with *plenty of newcomer issues (mainly mechanical), probably a few electrical (ESC, Batteries), and most importantly, you have to learn to drive skillfully..

You wont do well at any of these if you are *also debugging your custom prototype control system.

A combat robot is an *incredibly hostile environment for prototype electronics to live in..

Metal fragments, swarf, rubber and dust flying around (look inside a bot after an event, you would think they have been 4WDing in the desert)

and regular G-Force shocks that are almost inconceivably violent to most newcomers. Imagine throwing a 13Kg sledgehammer moving at 20-30kph (another bot) at the box your project is mounted in, or even better, a hit from a spinning bar doing several hundred Kph.

Shock Forces in the *thousands of G arent uncommon. I have seen through hole components torn right off circuit boards and chips ripped out of machine-pin sockets just from impacts.

Its just not a place you want to be trying to test and develop a concoction of beta code, inter-board connectors and custom components.

If you believe you have an idea that will confer a *serious benefit over the standard control system, by all means develop and test it outside the arena, then add it to the 'bot *After the bots electro/mech systems are debugged and proven.

Sitting still, twitching, or having poor control in the arena, is an invitation to have your bots face (and other parts) ripped off.. You want the simplest, most reliable control system you can find to start with..

Assuming of course, that your goal is to enter the arena with a reasoanble chance of winning or surviving a match or two _________________Great minds discuss ideas. Average minds discuss events. Small minds discuss people

Mon Sep 21, 2015 2:55 pm

0xFFFF

Joined: 17 Sep 2015
Posts: 18
Location: SE Victoria

quote:Originally posted by Valen:
advice for newcomers, invent as few wheels as possible.

I was going to go against the grain to begin with because I have some kick a** industrial radio equipment but I'm not sure how well it will perform against impacts and extreme heat.
I can see that a lot of the high end transceivers are using Cypress or TI chip-sets. They are easy enough to implement but all I'm doing is saving a few coins and adding complexity / more points of failure.
I'm following your advice Valen.

quote:Originally posted by Valen:
...but newer ones seem to be prone to having issues binding when you turn the RX on.

Is this a new issue? ...something that is likely going to be resolved with a firmware fix?

So HobbyKing looks like the way to go! Very cheap compared to what I was expecting. But then, I wasn't really thinking about purchasing RF gear.
Any opinions on Walkera?

Do Receivers only output PWM?

How does the use of these 2.4MHz radios get around the second channel rule? I forget where I read that. There are a lot of dead links on this forum.

Mon Sep 21, 2015 3:07 pm

miles&JulesExperienced Roboteer

Joined: 19 May 2010
Posts: 3970
Location: ipswich QLD

Everyone just uses the hobby king stuff cause it just works - the the software to programme it is really crap- though and you need to buy the usb connector to mix it for robot drive- and buy a few extra recievers cause they can get broken in battle and are only $10- the oranges can work but ours takes 30 seconds to bind when you turn it on and its a bit nerve racking wondering if it will connect moments before a match_________________Miles Blow - Julie Pitts
www.mulesfilm.com.auwww.wombokforest.com.au

-Pickasso- Vivid Sportsman champion 2015

Mon Sep 21, 2015 3:24 pm

Cyber

Joined: 26 Aug 2015
Posts: 59
Location: Melbourne

hey mate

as has been said, if you're going to go down a fancy route make sure the electronics are up to the rough and tumble etc

that said... I developed a way of driving a left/right motor driven 'tank style' bot using a wheel-and-trigger style controller. It's simple to set up and any arduino with at least 4 digital pins will do the job with any R/C compatible receiver and any R/C compatible ESC

the code is here: https://github.com/psYbR/rc-trigger-control-arduino along with instructions to set it up. You could very easily replace the R/C receiver with another method of control (PS controller, other radio gear, etc) and use the existing code with a few tweaks to drive your ESCs. Hit me up if you want some more info. Just suggesting it as I found it a lot easier and natural-feeling to drive than a dual-stick type controller. Also I already had the radio gear

Mon Sep 21, 2015 3:36 pm

Spockie-TechSite Admin

Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia

All you need to get rid of dual-stick "Tank" style steering is to enable "Elevon" mixing in most modern transmitters..

This merges the "Elevator" (y) and "Aileron" (x) sticks into channels 1 and 2 and allows you to drive with a single stick or wheel/trigger radio.

Ancient transmitters without in-built mixing can buy a separate external "mixer" board that goes between the RX and the ESC and does it onboard the robot. but its easier to do at the TX if your TX was made this decade_________________Great minds discuss ideas. Average minds discuss events. Small minds discuss people

Mon Sep 21, 2015 3:58 pm

0xFFFF

Joined: 17 Sep 2015
Posts: 18
Location: SE Victoria

quote:Originally posted by Spockie-Tech:
All you need to get rid of dual-stick "Tank" style steering is to enable "Elevon" mixing in most modern transmitters..

quote:Originally posted by Spockie-Tech:
All you need to get rid of dual-stick "Tank" style steering is to enable "Elevon" mixing in most modern transmitters..

the things you learn
after
you spend hours writing the code Still, saved me spending any money at all on a radio

Mon Sep 21, 2015 4:51 pm

Spockie-TechSite Admin

Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia

Tank style control just means left-stick = left motor drive, right stick = right motor drive. so both forward = forward, both back = reverse, opposite = turn etc.

With Elevon mixing, Elevator forward = both motors forward, elevator back = both motors backwards, and any "aileron" input (x, side to side) stick movement adjusts the balance between left and right channels. so full left aileron (x on the stick) = left motor full speed one way, right motor the other way, with the reverse for full right stick.

So, you get exactly the same amount of motor control, with the ability to spin on the spot, do gradual turns etc, with the same maneuverability..

The only difference is that when mixing, its all controller by the one X/Y stick, instead of two sticks Y-only.

Most people learn to drive with the mixed right-side single-stick control, probably 80-90% of drivers drive this way. This leaves the left stick (throttle/Rudder) for activating weapon motors or articulated arms etc.

a few (mainly those with RC Car experience) prefer wheel/trigger radios.

A little known emergency hack is you can use a non-mixed TX setup as if it was mixed, merely by holding the radio at 45-degrees., so when you push "forward" (relative to you) on the stick, you are actually taking both channels 1(y)+2(x) forward by means of actually pushing the stick diagonally (relative to the TX body). It doesnt work very well, since the X/Y springs make it feel weird and difficult to go *straight forward, but it works in a pinch._________________Great minds discuss ideas. Average minds discuss events. Small minds discuss people

Mon Sep 21, 2015 5:07 pm

martoExperienced Roboteer

Joined: 08 Jul 2004
Posts: 5459
Location: Brisbane, QLD

"TX HACK" (someone kill me now)

Simply Rotate your TX until the mixing returns to something usable. Worst case I always orient so left and right is correct even if forward/reverse is backwards.

As for the dead links... well the forum is what 13yrs old now and its the internet not really a lot you can do.

I think there are plenty of ways to employ custom code and electronics in sportsman designs. KE weapons are speed limited to 400RPM, come up with a sensor and PWM speed controller to vary motor torque as weapon makes contact. For electric lifter devise method of parking forks jaws etc. Dynamic brake hammer mechanism
Controls clamping so motors arenít stalled.etc

The basic Hobyking radio is programmed by computer works adequately wonít spoil your day if RX destroyed.

The speed controller in the picture of NetBot is an IBC . It already has mixing._________________Satisfaction is proportional to effort and results.

Mon Sep 21, 2015 6:23 pm

NickExperienced Roboteer

Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW

Another thing to keep in mind when selecting a radio is the rule about failsafing. A failsafe radio will send the receiver servo outputs to designated safe settings to stop the drive & weapon motors. This has to be supported in both the transmitter AND the receiver._________________Australian 2015 Featherweight champion
UK 2016 Gladiator champion